Crowds taunted and cursed security forces barricading central Rangoon overnight, as the junta tried to prevent more mass protests against Burma's 45 years of military rule and deepening economic hardship.

Meanwhile Foreign Minister Alexander Downer said Australian diplomats feared the true death toll in the country was much higher than has been reported so far, and could be in the hundreds.

Potentially deadly games of cat and mouse went on for hours around the barbed-wire barriers in a city terrified of a repeat of 1988, when the army killed an estimated 3,000 people in crushing an uprising.

Few Buddhist monks were among the crowds, unlike in previous days, after soldiers ransacked 10 monasteries on Thursday and carted off hundreds inside.

When the troops charged, the protesters vanished into narrow side streets, only to emerge elsewhere to renew their abuse until darkness fell and an overnight curfew took effect.

"We only want democracy," some yelled in English. "May the people who beat monks be struck down by lightning," others chanted in Burmese.

Despite the visceral anger in their voices, far fewer protesters turned out in Rangoon than earlier in the week, when they had walked alongside thousands of maroon-robed monks.

Shots were fired on Friday but there was no word of more casualties a day after troops swept protesters from the center of Rangoon, giving them 10 minutes to leave or be shot.

Troops fired on several crowds on Thursday and state-run television said nine people were killed.

Downer, Brown comment

"The Burmese official estimate of 10 dead is likely to be a real exaggeration [sic]," Mr Downer said. "I think the numbers are going to be substantially higher than that. I think they could be multiples of ten higher."

His comments were echoed by British Prime Minister Gordon Brown.

"I am afraid we believe the loss of life is far greater than is being reported," Mr Brown said on Friday after talking by telephone with US President George W Bush and Chinese Premier Wen Jiabao.

There has been no word on the fate of the monks, who turned what began as small protests against shock fuel price rises last month into a mass uprising when they lent their moral weight to demonstrations against the ruling generals.

Burma's main internet link has been cut off and internet cafes in Rangoon are closed. Several newspapers have also stopped publishing. Witnesses in the city say soldiers have beaten and arrested people found with mobile phones or cameras.

In other developments, UN special envoy Ibrahim Gambari was in Singapore and is expected to arrive in Burma later today.

Some monks told foreign Burmese-language broadcasters they were not going to give up. Speaking anonymously, they said a "united front" of clergy, students and activists had been formed to continue the struggle.

Mr Bush and Mr Brown discussed the need to maintain international pressure on Burma's rulers and the White House condemned the crackdown as "barbaric."

Asked whether Mr Bush and Mr Brown talked about the possibility of encouraging Burma's people to overthrow their government if protests grew into a full-scale uprising, White House spokesman Scott Stanzel said that would be "a hypothetical."

"We certainly support the people who are marching for democracy and peace," he said.

The European Union summoned Burma's senior diplomat in Brussels and warned him of tighter sanctions.

EU experts looked into possible restrictions on exports from Burma of timber, precious metals and stones but did not reach any decisions, one diplomat said. Investments by specific Europeans in the country were not raised, he said.

Activist Mark Farmaner of the Burma Campaign UK called the EU sanctions "pathetic" and said a freeze on assets had netted less than 7,000 euros in all 27 EU member states and many countries allowed companies to do business in Burma.

Russian President Vladimir Putin said sanctions were premature but that he was sorry to hear about civilian deaths.

"As far as sanctions are concerned, this is a topic to be especially considered in the United Nations," said Mr Putin.

Russia is, like China, a veto-wielding UN Security Council member and has shown growing interest in energy cooperation with Burma. China, the main backer of Burma's military government, has flatly ruled out backing sanctions.

The junta told diplomats summoned to its new jungle capital of Naypyidaw that it was "committed to showing restraint in its response to the provocations," one of those present said.

There were protests across Asia, with many people wearing red to symbolise the blood spilled in Burma.